B0990
Body Control Module Internal Fault
The body control module (BCM) has detected an internal fault and may need to be replaced.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Warning light or symbol related to the affected system
- Comfort or safety function impaired
Common causes
Ordered by how often each turns out to be the cause.
- BCM internal hardware faultCommon
- Voltage spike damage from jump-startPossible
- Water intrusion at modulePossible
Parts involved
- Body Control Module
B0990 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.